383 research outputs found

    Crescimento e desenvolvimento de pessegueiros 'Chimarrita' e 'Maciel' sobre diferentes porta-enxertos e locais de cultivo.

    Get PDF
    Objetivou-se com o presente trabalho avaliar a influência dos porta-enxertos no que se refere ao crescimento vegetativo e desenvolvimento dos pessegueiro 'Chimarrita' e 'Maciel' em três locais de cultivo. O experimento foi desenvolvido em três locais de cultivo: 1 (Embrapa Uva e Vinho), 2 (EEA UFRGS) e 3 (CAP UFPel), em três anos. As cultivares de pessegueiro utilizadas foram: 'Chimarrita' e 'Maciel' enxertadas sobre seis porta-enxertos ('Aldrighi', 'Capdeboscq', 'Flordaguard', 'Nemaguard', 'Okinawa' e Umezeiro), no espaçamento 1,5 X 5,0m e conduzidas no sistema em ?V?. Foram avaliados: volume de copa, diâmetro de tronco, massa fresca da poda, produção por planta acumulada, comprimento, espessura, gemas floríferas e densidade florífera do ramo produtivo. Também foi avaliado de forma visual o ponto de enxertia. O porta-enxerto Umezeiro induziu menor vigor nos três locais de cultivo estudados e na média dos três anos. Ele pode ser indicado para utilização sob 'Maciel' nas condições edafoclimáticas do local 3. No local 1 o porta-enxerto, 'Nemaguard' possui alto vigor e maior produção acumulada, sendo o mais indicado. Já para o local 2, os porta-enxertos 'Capdeboscq', 'Okinawa' e 'Flordaguard' são os mais indicados. Os porta-enxertos afetam as características de crescimento e desenvolvimento das cultivares 'Chimarrita' e 'Maciel', o vigor destas é menor sobre o portaenxerto Umezeiro nos três locais de cultivo. Todos os portaenxertos podem ser indicados para os três locais de cultivo, com exceção do Umezeiro, que somente pode ser indicado em combinação com a cultivar 'Maciel' no local 3

    TOWARDS GESTURE-BASED MULTI-USER INTERACTIONS IN COLLABORATIVE VIRTUAL ENVIRONMENTS

    Get PDF
    We present a virtual reality (VR) setup that enables multiple users to participate in collaborative virtual environments and interact via gestures. A collaborative VR session is established through a network of users that is composed of a server and a set of clients. The server manages the communication amongst clients and is created by one of the users. Each user's VR setup consists of a Head Mounted Display (HMD) for immersive visualisation, a hand tracking system to interact with virtual objects and a single-hand joypad to move in the virtual environment. We use Google Cardboard as a HMD for the VR experience and a Leap Motion for hand tracking, thus making our solution low cost. We evaluate our VR setup though a forensics use case, where real-world objects pertaining to a simulated crime scene are included in a VR environment, acquired using a smartphone-based 3D reconstruction pipeline. Users can interact using virtual gesture-based tools such as pointers and rulers

    History and philosophy of science in Biology teaching

    Get PDF
    Neste trabalho, buscamos evidenciar a concepção de História da Biologia que é veiculada nos livros didáticos. Para tanto, analisamos três coleções de livros de Biologia destinados ao Ensino Médio, e alguns livros universitários usados em cursos de formação de professores. Ao analisar este material curricular foi possível observar que a história apresentada é desvinculada do contexto cultural de cada período histórico, o que pode levar o aluno a construir uma falsa representação da ciência e do fazer científico.In this work, we search forto evidences the conception of the History of Biology being is propagated in textbooks. We analyze three Biology book collections designed estined forto middle schooledium education, and some university books used in teacher education courses. When analyzing this curricular material it was possible to observe that the history of biology presented is disengaged from entailedofthe cultural context of each historical period, and this what can lead the student to construct a false representation of science and of scientific meaning making

    Organogenesis and embryogenesis in several hypericum perforatum genotypes

    Get PDF
    St John’s wort (Hypericum perforatum) is a valuable plant used as a herbal remedy or in phytopharmaceutical drugs to treat a variety of physical ailments. Much research has been performed to study the biochemical production of secondary metabolites of in vitro cultured plants or organs. However, all of these studies have looked at the regeneration of plants from explants in only one genotype. In addition, no study has revealed the mechanism of plant regeneration in H. perforatum, i.e. organogenesis or somatic embryogenesis. We found that different genotypes Helos, Topas, Elixir, and Numi responded similarly to regeneration medium. The regeneration responses (i.e. callus, root, or shoot production) of identical explants from different genotypes were similar. However, the source of explant material (leaves, hypocotyls, and roots) from the same genotype had significant effects on the response to media and plant regeneration frequency. Using scanning electron microscopy and light microscopy, the progress of organogenesis and embryogenesis under similar culture conditions was recorded. Root segments were the most responsive explants, producing the maximum number of shoots per explant of all the genotypes.Fundação para a Ciência e a Tecnologia (FCT) - POCTI/AGR/40 283/2001, SFRH/BPD/17102/2004

    EL ESTADO NACIÓN Y LA CONTRADICCIÓN CAPITAL-TRABAJO EN ARGENTINA: SOBRE LAS FUNCIONES DE LEGITIMACIÓN Y ACUMULACIÓN DE LOS PROGRAMAS SOCIALES DE EMPLEO ARGENTINOS (2002-2011)

    Get PDF
    En el marco del proceso de reestructuración del capital, la presente investigación se propone analizar cómo los programas sociales de empleo argentinos, así como los discursos oficiales a ellos referidos, responden a las históricas funciones de acumulación y legitimación de los gobiernos capitalistas (2002-2011), con el propósito de problematizar sobre el papel de los primeros en la contradicción contemporánea capital- trabajo en Argentina, y- desde un nivel mayor de abstracción-, sobre el papel de los Estados nacionales en el proceso de acumulación del capital, principalmente en lo que refiere a la gestión de la fuerza de trabajo. Para ello se utilizó una metodología cualitativa basada en el Análisis del Contenido de la normativa y discursos oficiales referida a la creación, implementación y contextualización de los programas. Concluimos la presente investigación documental señalando el carácter funcional de los programas al proceso de reestructuración del capital. Desde sus orígenes, los programas sociales de empleo constituyen una de las tantas estrategias utilizadas por este último para valorizarse y transitar sus crisis cíclicas y estructurales: su implementación, además de reproducir y disponer fuerza de trabajo necesaria para la acumulación del capital, viabiliza los procesos de flexibilización productiva y del trabajo. PALABRAS CLAVES: Estado, Capital-Trabajo, Programas Sociales de Empleo

    An outbreak of crayfish rickettsiosis caused by Coxiella cheraxi in redclaw crayfish (Cherax quadricarinatus) imported to Israel from Australia

    Get PDF
    The redclaw crayfish (Cherax quadricarinatus) is a freshwater decapod crustacean, cultured in numerous countries worldwide for both food and ornamental purposes. Redclaw crayfish has become an important aquaculture species due to its physical and biological traits, relatively easy breeding, and a short growing-out period to reach commercial size. Bacterial infections are the second-most studied pathogens of freshwater crayfish. However, redclaw crayfish rickettsiosis, caused by Coxiella cheraxi, was reported in only a few scientific papers in the early 2000s, in Australia and Ecuador. Coxiella cheraxi is a rod-shaped intracellular bacterium that can cause mortality of 22%−80% in naturally infected crayfish. In experimental infections, mortality rates may be even higher (40%−90%). Coxiella cheraxi is closely related to Coxiella burnetii, the agent of Q-fever, which affects ruminants (goats, sheep, and cattle) and occasionally may cause zoonotic infections. According to the scientific knowledge available, C. cheraxi is a species-specific pathogen because it has been only detected in Cherax quadricarinatus and thus far, there is no evidence of a zoonotic potential. In this study, we describe an outbreak of rickettsiosis in a batch of redclaw crayfish imported to Israel from an Australian hatchery, observed 2 months after introduction in a quarantine facility. Initial mortality was evaluated through histopathology, revealing infection by rickettsia-like organisms (RLO) that were subsequently investigated by molecular analysis and transmission electron microscopy examination. Phylogenetic analysis revealed that the detected RLO were closely related to C. cheraxi from a single source (Australian strain TO98), available in free publicly accessible databases. After 5 months in quarantine, almost 99% of the crayfish population had died. Our findings raise valuable questions related to aquatic animal trade and the importance of mitigation measures, such as quarantine and routine diagnostic procedures, to limit the spread of infectious diseases

    Hypericum sp.: essential oil composition and biological activities

    Get PDF
    Phytochemical composition of Hypericum genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization as well as biological activities of H. perforatum crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett in Nat Prod Commun 5(9):1493–1506, 2010; Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/ 13283/2003

    EGFR interacts with the fusion protein of respiratory syncytial virus strain 2-20 and mediates infection and mucin expression.

    Get PDF
    Respiratory syncytial virus (RSV) is the major cause of viral lower respiratory tract illness in children. In contrast to the RSV prototypic strain A2, clinical isolate RSV 2-20 induces airway mucin expression in mice, a clinically relevant phenotype dependent on the fusion (F) protein of the RSV strain. Epidermal growth factor receptor (EGFR) plays a role in airway mucin expression in other systems; therefore, we hypothesized that the RSV 2-20 F protein stimulates EGFR signaling. Infection of cells with chimeric strains RSV A2-2-20F and A2-2-20GF or over-expression of 2-20 F protein resulted in greater phosphorylation of EGFR than infection with RSV A2 or over-expression of A2 F, respectively. Chemical inhibition of EGFR signaling or knockdown of EGFR resulted in diminished infectivity of RSV A2-2-20F but not RSV A2. Over-expression of EGFR enhanced the fusion activity of 2-20 F protein in trans. EGFR co-immunoprecipitated most efficiently with RSV F proteins derived from "mucogenic" strains. RSV 2-20 F and EGFR co-localized in H292 cells, and A2-2-20GF-induced MUC5AC expression was ablated by EGFR inhibitors in these cells. Treatment of BALB/c mice with the EGFR inhibitor erlotinib significantly reduced the amount of RSV A2-2-20F-induced airway mucin expression. Our results demonstrate that RSV F interacts with EGFR in a strain-specific manner, EGFR is a co-factor for infection, and EGFR plays a role in RSV-induced mucin expression, suggesting EGFR is a potential target for RSV disease
    corecore